Internet Protocol, or IP, is utilized to transmit packets of information over computer networks and forms the protocol backbone of the Internet. The Internet is commonly known as the networked communication system interconnecting various sub-networks throughout the world. Various users of the term “Internet” may utilize the term interchangeably or in substitution for other terms such as “internet” and “World Wide Web”. It is to be recognized and understood, however, that the Internet may refer to other internetworking systems and protocols for linking nodes, either public or private, existing or yet to be developed. Internet Protocol defines how various nodes on the network are addressed and grouped together and how packets are labeled to route the packets from the source node in the network to the destination node. Thus, Internet Protocol provides labeling and routing for effectively all data transmitted over the Internet.
In general, the Internet starts with what is commonly referred to as the physical layer, comprised of the actual hardware which comprises the Internet, from individual routers to the data transmission lines over which data is transmitted. The media access control layer, or MAC layer, is an interface between the physical layer of the Internet and sub-networks such as local area networks and so forth which allow individual nodes to communicate directly with one another without respect to the Internet. The media access control layer functions by providing one unique address or serial number to each device in a sub-network, thereby allowing the members of a sub-network to communicate across local repeaters and hubs but not over the Internet.
The Internet Protocol then interworks between the sub-networks over the Internet. The Internet Protocol creates a system which is relatively fast and simple. Any packet which is sent onto the Internet with an appropriate header will be guided through the various nodes of the Internet. Because the Internet Protocol does not necessarily seek to ensure that all data reaches its destination, with corrupted packets simply being deemed lost, not all packets will reach the destination. However, the Internet Protocol does ensure that an attempt will be made to transmit every data packet placed on the Internet to the node included in the destination field of the packet's header information, and generally the overwhelming majority of data packets placed on the Internet do, in fact, reach their destination.